Top Interview Questions For A Data Engineer Job Profile

The increasing data has given a rise to the number of professionals who can draw valuable insights from it. Data engineer is one of the most popular positions in companies and is crucial to the analytics team. Data analysts and other roles are often confused with data engineer roles, but the latter is usually involved in building infrastructure or framework necessary for data generation. They work on the architecture aspect of data, like data collection, data storage, and data management, among others.

Having said this, every company may have its own definition of what a data engineer, the hiring process remains largely the same and so does the interview questions. If you are applying for a data engineer role, these are the most likely questions that you might be asked:

General Questions

What are the different types of design schemas in data modeling?

There are two schemas in data modeling: Star schema and the other is Snowflake Schema.

How is the Hadoop database different from the traditional Relational Database Management System?

The Hadoop database is a column-oriented database which has a flexible schema to add columns on the fly. It is equipped with sparse tables with tight integration of MR (market research) and horizontal scalability, very efficient for semi-structured and unstructured data.

RDMS is designed for the row-oriented databases with a fixed schema. It is optimized for joins and not for sparse tables. Not having integration with MR makes another major difference from Hadoop. RDBMS is preferred for the structured data

Elaborate on Hadoop distributed file system

Hadoop can work directly with any scalable distributed file system such as Local FS, HFTP FS, S3 FS, and others, but the most common file system used by Hadoop is the HDFS

The Hadoop Distributed File System is built on the Google File System (GFS) and contribute a distributed file system that is designed to run on large clusters (thousands of computers) of small computer machines in a definitive and accurate manner.

HDFS uses a master/slave architecture where master consists of a single NameNode that manages the file system metadata and one or more slave DataNodes that store the actual data.

Technical Questions: Get Set Sode

Data science has an in-depth coding involved which requires the programming knowledge of various languages such as python, java. Statistical software as R programming. Database systems like Hadoop. Testing tools of ETL and task automation platforms like Powershell. Here are a few questions asked on these topics.

Explain what is the importance of brackets in PowerShell?

Square Brackets []: They define arbitrary items, and they are not used frequently.

Mention the three ways that PowerShell uses to ‘Select’

The most familiar and widely used way is the Wmiobject technique, in this technique we use ‘-query’ to introduce a classic ‘Select * from’ a phrase

The second widely used method used for ‘Select’ in PowerShell is Select-String. Which completely checks for a word, phrase or any pattern match.

The third way is Select-Object.

Conclusion

Getting a data engineer post is tough but not impossible. With numerous complications associated with collecting and managing data, this field is now hosting to a wide array of jobs and designations. Having the ability to integrate knowledge, skill and analytical approach is essential. It’s not just about data science; it’s about having the ability to transform that data into visualization. Your strategy will only be as good as the data, so take the time to graduate with skills required to be a data engineer whom employers will want to hire.